SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50d1c14df0a65843ed132c4d1ff190e647af56d94505fe306b119aa6ed582dd5' 
  AND token = 'l2649sdNflQ5OrIoH2TyVvbqyYPdTEdcLM5qzo2tXYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}